﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo4
{
    class Circle : Shape
    {

        protected double radius;
        public double Radius
        { 
            get { return this.radius; }
            set { this.radius = value; }

}
        
        public override void GetArea(double a )
        {
            //base.GetArea();
           
            double result = 3.14 * radius*radius;
            
            Console.WriteLine("圆形面积"+result);
        }
    }
}
